?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge tag 'ceph-for-4.13-rc8' of git://github.com/ceph/ceph-client
[linux/fpc-iii.git] / drivers / usb / class / cdc-wdm.c
blob8f972247b1c1ac4d41faebe390a4c9ac9a308960
1 /*
2 * cdc-wdm.c
3 *
4 * This driver supports USB CDC WCM Device Management.
5 *
6 * Copyright (c) 2007-2009 Oliver Neukum
7 *
8 * Some code taken from cdc-acm.c
9 *
10 * Released under the GPLv2.
11 *
12 * Many thanks to Carl Nordbeck
13 */
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/ioctl.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/uaccess.h>
21 #include <linux/bitops.h>
22 #include <linux/poll.h>
23 #include <linux/usb.h>
24 #include <linux/usb/cdc.h>
25 #include <asm/byteorder.h>
26 #include <asm/unaligned.h>
27 #include <linux/usb/cdc-wdm.h>
28
29 /*
30 * Version Information
31 */
32 #define DRIVER_VERSION "v0.03"
33 #define DRIVER_AUTHOR "Oliver Neukum"
34 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
35
36 static const struct usb_device_id wdm_ids[] = {
37 {
38 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
39 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
40 .bInterfaceClass = USB_CLASS_COMM,
41 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
42 },
43 { }
44 };
45
46 MODULE_DEVICE_TABLE (usb, wdm_ids);
47
48 #define WDM_MINOR_BASE 176
49
50
51 #define WDM_IN_USE 1
52 #define WDM_DISCONNECTING 2
53 #define WDM_RESULT 3
54 #define WDM_READ 4
55 #define WDM_INT_STALL 5
56 #define WDM_POLL_RUNNING 6
57 #define WDM_RESPONDING 7
58 #define WDM_SUSPENDING 8
59 #define WDM_RESETTING 9
60 #define WDM_OVERFLOW 10
61
62 #define WDM_MAX 16
63
64 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
65 #define WDM_DEFAULT_BUFSIZE 256
66
67 static DEFINE_MUTEX(wdm_mutex);
68 static DEFINE_SPINLOCK(wdm_device_list_lock);
69 static LIST_HEAD(wdm_device_list);
70
71 /* --- method tables --- */
72
73 struct wdm_device {
74 u8 *inbuf; /* buffer for response */
75 u8 *outbuf; /* buffer for command */
76 u8 *sbuf; /* buffer for status */
77 u8 *ubuf; /* buffer for copy to user space */
78
79 struct urb *command;
80 struct urb *response;
81 struct urb *validity;
82 struct usb_interface *intf;
83 struct usb_ctrlrequest *orq;
84 struct usb_ctrlrequest *irq;
85 spinlock_t iuspin;
86
87 unsigned long flags;
88 u16 bufsize;
89 u16 wMaxCommand;
90 u16 wMaxPacketSize;
91 __le16 inum;
92 int reslength;
93 int length;
94 int read;
95 int count;
96 dma_addr_t shandle;
97 dma_addr_t ihandle;
98 struct mutex wlock;
99 struct mutex rlock;
100 wait_queue_head_t wait;
101 struct work_struct rxwork;
102 int werr;
103 int rerr;
104 int resp_count;
105
106 struct list_head device_list;
107 int (*manage_power)(struct usb_interface *, int);
108 };
109
110 static struct usb_driver wdm_driver;
111
112 /* return intfdata if we own the interface, else look up intf in the list */
113 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
114 {
115 struct wdm_device *desc;
116
117 spin_lock(&wdm_device_list_lock);
118 list_for_each_entry(desc, &wdm_device_list, device_list)
119 if (desc->intf == intf)
120 goto found;
121 desc = NULL;
122 found:
123 spin_unlock(&wdm_device_list_lock);
124
125 return desc;
126 }
127
128 static struct wdm_device *wdm_find_device_by_minor(int minor)
129 {
130 struct wdm_device *desc;
131
132 spin_lock(&wdm_device_list_lock);
133 list_for_each_entry(desc, &wdm_device_list, device_list)
134 if (desc->intf->minor == minor)
135 goto found;
136 desc = NULL;
137 found:
138 spin_unlock(&wdm_device_list_lock);
139
140 return desc;
141 }
142
143 /* --- callbacks --- */
144 static void wdm_out_callback(struct urb *urb)
145 {
146 struct wdm_device *desc;
147 desc = urb->context;
148 spin_lock(&desc->iuspin);
149 desc->werr = urb->status;
150 spin_unlock(&desc->iuspin);
151 kfree(desc->outbuf);
152 desc->outbuf = NULL;
153 clear_bit(WDM_IN_USE, &desc->flags);
154 wake_up(&desc->wait);
155 }
156
157 /* forward declaration */
158 static int service_outstanding_interrupt(struct wdm_device *desc);
159
160 static void wdm_in_callback(struct urb *urb)
161 {
162 struct wdm_device *desc = urb->context;
163 int status = urb->status;
164 int length = urb->actual_length;
165
166 spin_lock(&desc->iuspin);
167 clear_bit(WDM_RESPONDING, &desc->flags);
168
169 if (status) {
170 switch (status) {
171 case -ENOENT:
172 dev_dbg(&desc->intf->dev,
173 "nonzero urb status received: -ENOENT\n");
174 goto skip_error;
175 case -ECONNRESET:
176 dev_dbg(&desc->intf->dev,
177 "nonzero urb status received: -ECONNRESET\n");
178 goto skip_error;
179 case -ESHUTDOWN:
180 dev_dbg(&desc->intf->dev,
181 "nonzero urb status received: -ESHUTDOWN\n");
182 goto skip_error;
183 case -EPIPE:
184 dev_err(&desc->intf->dev,
185 "nonzero urb status received: -EPIPE\n");
186 break;
187 default:
188 dev_err(&desc->intf->dev,
189 "Unexpected error %d\n", status);
190 break;
191 }
192 }
193
194 /*
195 * only set a new error if there is no previous error.
196 * Errors are only cleared during read/open
197 */
198 if (desc->rerr == 0)
199 desc->rerr = status;
200
201 if (length + desc->length > desc->wMaxCommand) {
202 /* The buffer would overflow */
203 set_bit(WDM_OVERFLOW, &desc->flags);
204 } else {
205 /* we may already be in overflow */
206 if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
207 memmove(desc->ubuf + desc->length, desc->inbuf, length);
208 desc->length += length;
209 desc->reslength = length;
210 }
211 }
212 skip_error:
213 set_bit(WDM_READ, &desc->flags);
214 wake_up(&desc->wait);
215
216 if (desc->rerr) {
217 /*
218 * Since there was an error, userspace may decide to not read
219 * any data after poll'ing.
220 * We should respond to further attempts from the device to send
221 * data, so that we can get unstuck.
222 */
223 service_outstanding_interrupt(desc);
224 }
225
226 spin_unlock(&desc->iuspin);
227 }
228
229 static void wdm_int_callback(struct urb *urb)
230 {
231 int rv = 0;
232 int responding;
233 int status = urb->status;
234 struct wdm_device *desc;
235 struct usb_cdc_notification *dr;
236
237 desc = urb->context;
238 dr = (struct usb_cdc_notification *)desc->sbuf;
239
240 if (status) {
241 switch (status) {
242 case -ESHUTDOWN:
243 case -ENOENT:
244 case -ECONNRESET:
245 return; /* unplug */
246 case -EPIPE:
247 set_bit(WDM_INT_STALL, &desc->flags);
248 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
249 goto sw; /* halt is cleared in work */
250 default:
251 dev_err(&desc->intf->dev,
252 "nonzero urb status received: %d\n", status);
253 break;
254 }
255 }
256
257 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
258 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
259 urb->actual_length);
260 goto exit;
261 }
262
263 switch (dr->bNotificationType) {
264 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
265 dev_dbg(&desc->intf->dev,
266 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
267 le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
268 break;
269
270 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
271
272 dev_dbg(&desc->intf->dev,
273 "NOTIFY_NETWORK_CONNECTION %s network\n",
274 dr->wValue ? "connected to" : "disconnected from");
275 goto exit;
276 case USB_CDC_NOTIFY_SPEED_CHANGE:
277 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
278 urb->actual_length);
279 goto exit;
280 default:
281 clear_bit(WDM_POLL_RUNNING, &desc->flags);
282 dev_err(&desc->intf->dev,
283 "unknown notification %d received: index %d len %d\n",
284 dr->bNotificationType,
285 le16_to_cpu(dr->wIndex),
286 le16_to_cpu(dr->wLength));
287 goto exit;
288 }
289
290 spin_lock(&desc->iuspin);
291 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
292 if (!desc->resp_count++ && !responding
293 && !test_bit(WDM_DISCONNECTING, &desc->flags)
294 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
295 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
296 dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
297 }
298 spin_unlock(&desc->iuspin);
299 if (rv < 0) {
300 clear_bit(WDM_RESPONDING, &desc->flags);
301 if (rv == -EPERM)
302 return;
303 if (rv == -ENOMEM) {
304 sw:
305 rv = schedule_work(&desc->rxwork);
306 if (rv)
307 dev_err(&desc->intf->dev,
308 "Cannot schedule work\n");
309 }
310 }
311 exit:
312 rv = usb_submit_urb(urb, GFP_ATOMIC);
313 if (rv)
314 dev_err(&desc->intf->dev,
315 "%s - usb_submit_urb failed with result %d\n",
316 __func__, rv);
317
318 }
319
320 static void kill_urbs(struct wdm_device *desc)
321 {
322 /* the order here is essential */
323 usb_kill_urb(desc->command);
324 usb_kill_urb(desc->validity);
325 usb_kill_urb(desc->response);
326 }
327
328 static void free_urbs(struct wdm_device *desc)
329 {
330 usb_free_urb(desc->validity);
331 usb_free_urb(desc->response);
332 usb_free_urb(desc->command);
333 }
334
335 static void cleanup(struct wdm_device *desc)
336 {
337 kfree(desc->sbuf);
338 kfree(desc->inbuf);
339 kfree(desc->orq);
340 kfree(desc->irq);
341 kfree(desc->ubuf);
342 free_urbs(desc);
343 kfree(desc);
344 }
345
346 static ssize_t wdm_write
347 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
348 {
349 u8 *buf;
350 int rv = -EMSGSIZE, r, we;
351 struct wdm_device *desc = file->private_data;
352 struct usb_ctrlrequest *req;
353
354 if (count > desc->wMaxCommand)
355 count = desc->wMaxCommand;
356
357 spin_lock_irq(&desc->iuspin);
358 we = desc->werr;
359 desc->werr = 0;
360 spin_unlock_irq(&desc->iuspin);
361 if (we < 0)
362 return usb_translate_errors(we);
363
364 buf = memdup_user(buffer, count);
365 if (IS_ERR(buf))
366 return PTR_ERR(buf);
367
368 /* concurrent writes and disconnect */
369 r = mutex_lock_interruptible(&desc->wlock);
370 rv = -ERESTARTSYS;
371 if (r)
372 goto out_free_mem;
373
374 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
375 rv = -ENODEV;
376 goto out_free_mem_lock;
377 }
378
379 r = usb_autopm_get_interface(desc->intf);
380 if (r < 0) {
381 rv = usb_translate_errors(r);
382 goto out_free_mem_lock;
383 }
384
385 if (!(file->f_flags & O_NONBLOCK))
386 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
387 &desc->flags));
388 else
389 if (test_bit(WDM_IN_USE, &desc->flags))
390 r = -EAGAIN;
391
392 if (test_bit(WDM_RESETTING, &desc->flags))
393 r = -EIO;
394
395 if (r < 0) {
396 rv = r;
397 goto out_free_mem_pm;
398 }
399
400 req = desc->orq;
401 usb_fill_control_urb(
402 desc->command,
403 interface_to_usbdev(desc->intf),
404 /* using common endpoint 0 */
405 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
406 (unsigned char *)req,
407 buf,
408 count,
409 wdm_out_callback,
410 desc
411 );
412
413 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
414 USB_RECIP_INTERFACE);
415 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
416 req->wValue = 0;
417 req->wIndex = desc->inum; /* already converted */
418 req->wLength = cpu_to_le16(count);
419 set_bit(WDM_IN_USE, &desc->flags);
420 desc->outbuf = buf;
421
422 rv = usb_submit_urb(desc->command, GFP_KERNEL);
423 if (rv < 0) {
424 desc->outbuf = NULL;
425 clear_bit(WDM_IN_USE, &desc->flags);
426 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
427 rv = usb_translate_errors(rv);
428 goto out_free_mem_pm;
429 } else {
430 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
431 le16_to_cpu(req->wIndex));
432 }
433
434 usb_autopm_put_interface(desc->intf);
435 mutex_unlock(&desc->wlock);
436 return count;
437
438 out_free_mem_pm:
439 usb_autopm_put_interface(desc->intf);
440 out_free_mem_lock:
441 mutex_unlock(&desc->wlock);
442 out_free_mem:
443 kfree(buf);
444 return rv;
445 }
446
447 /*
448 * Submit the read urb if resp_count is non-zero.
449 *
450 * Called with desc->iuspin locked
451 */
452 static int service_outstanding_interrupt(struct wdm_device *desc)
453 {
454 int rv = 0;
455
456 /* submit read urb only if the device is waiting for it */
457 if (!desc->resp_count || !--desc->resp_count)
458 goto out;
459
460 set_bit(WDM_RESPONDING, &desc->flags);
461 spin_unlock_irq(&desc->iuspin);
462 rv = usb_submit_urb(desc->response, GFP_KERNEL);
463 spin_lock_irq(&desc->iuspin);
464 if (rv) {
465 dev_err(&desc->intf->dev,
466 "usb_submit_urb failed with result %d\n", rv);
467
468 /* make sure the next notification trigger a submit */
469 clear_bit(WDM_RESPONDING, &desc->flags);
470 desc->resp_count = 0;
471 }
472 out:
473 return rv;
474 }
475
476 static ssize_t wdm_read
477 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
478 {
479 int rv, cntr;
480 int i = 0;
481 struct wdm_device *desc = file->private_data;
482
483
484 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
485 if (rv < 0)
486 return -ERESTARTSYS;
487
488 cntr = ACCESS_ONCE(desc->length);
489 if (cntr == 0) {
490 desc->read = 0;
491 retry:
492 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
493 rv = -ENODEV;
494 goto err;
495 }
496 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
497 clear_bit(WDM_OVERFLOW, &desc->flags);
498 rv = -ENOBUFS;
499 goto err;
500 }
501 i++;
502 if (file->f_flags & O_NONBLOCK) {
503 if (!test_bit(WDM_READ, &desc->flags)) {
504 rv = -EAGAIN;
505 goto err;
506 }
507 rv = 0;
508 } else {
509 rv = wait_event_interruptible(desc->wait,
510 test_bit(WDM_READ, &desc->flags));
511 }
512
513 /* may have happened while we slept */
514 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
515 rv = -ENODEV;
516 goto err;
517 }
518 if (test_bit(WDM_RESETTING, &desc->flags)) {
519 rv = -EIO;
520 goto err;
521 }
522 usb_mark_last_busy(interface_to_usbdev(desc->intf));
523 if (rv < 0) {
524 rv = -ERESTARTSYS;
525 goto err;
526 }
527
528 spin_lock_irq(&desc->iuspin);
529
530 if (desc->rerr) { /* read completed, error happened */
531 rv = usb_translate_errors(desc->rerr);
532 desc->rerr = 0;
533 spin_unlock_irq(&desc->iuspin);
534 goto err;
535 }
536 /*
537 * recheck whether we've lost the race
538 * against the completion handler
539 */
540 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
541 spin_unlock_irq(&desc->iuspin);
542 goto retry;
543 }
544
545 if (!desc->reslength) { /* zero length read */
546 dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
547 clear_bit(WDM_READ, &desc->flags);
548 rv = service_outstanding_interrupt(desc);
549 spin_unlock_irq(&desc->iuspin);
550 if (rv < 0)
551 goto err;
552 goto retry;
553 }
554 cntr = desc->length;
555 spin_unlock_irq(&desc->iuspin);
556 }
557
558 if (cntr > count)
559 cntr = count;
560 rv = copy_to_user(buffer, desc->ubuf, cntr);
561 if (rv > 0) {
562 rv = -EFAULT;
563 goto err;
564 }
565
566 spin_lock_irq(&desc->iuspin);
567
568 for (i = 0; i < desc->length - cntr; i++)
569 desc->ubuf[i] = desc->ubuf[i + cntr];
570
571 desc->length -= cntr;
572 /* in case we had outstanding data */
573 if (!desc->length) {
574 clear_bit(WDM_READ, &desc->flags);
575 service_outstanding_interrupt(desc);
576 }
577 spin_unlock_irq(&desc->iuspin);
578 rv = cntr;
579
580 err:
581 mutex_unlock(&desc->rlock);
582 return rv;
583 }
584
585 static int wdm_flush(struct file *file, fl_owner_t id)
586 {
587 struct wdm_device *desc = file->private_data;
588
589 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
590
591 /* cannot dereference desc->intf if WDM_DISCONNECTING */
592 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
593 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
594 desc->werr);
595
596 return usb_translate_errors(desc->werr);
597 }
598
599 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
600 {
601 struct wdm_device *desc = file->private_data;
602 unsigned long flags;
603 unsigned int mask = 0;
604
605 spin_lock_irqsave(&desc->iuspin, flags);
606 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
607 mask = POLLHUP | POLLERR;
608 spin_unlock_irqrestore(&desc->iuspin, flags);
609 goto desc_out;
610 }
611 if (test_bit(WDM_READ, &desc->flags))
612 mask = POLLIN | POLLRDNORM;
613 if (desc->rerr || desc->werr)
614 mask |= POLLERR;
615 if (!test_bit(WDM_IN_USE, &desc->flags))
616 mask |= POLLOUT | POLLWRNORM;
617 spin_unlock_irqrestore(&desc->iuspin, flags);
618
619 poll_wait(file, &desc->wait, wait);
620
621 desc_out:
622 return mask;
623 }
624
625 static int wdm_open(struct inode *inode, struct file *file)
626 {
627 int minor = iminor(inode);
628 int rv = -ENODEV;
629 struct usb_interface *intf;
630 struct wdm_device *desc;
631
632 mutex_lock(&wdm_mutex);
633 desc = wdm_find_device_by_minor(minor);
634 if (!desc)
635 goto out;
636
637 intf = desc->intf;
638 if (test_bit(WDM_DISCONNECTING, &desc->flags))
639 goto out;
640 file->private_data = desc;
641
642 rv = usb_autopm_get_interface(desc->intf);
643 if (rv < 0) {
644 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
645 goto out;
646 }
647
648 /* using write lock to protect desc->count */
649 mutex_lock(&desc->wlock);
650 if (!desc->count++) {
651 desc->werr = 0;
652 desc->rerr = 0;
653 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
654 if (rv < 0) {
655 desc->count--;
656 dev_err(&desc->intf->dev,
657 "Error submitting int urb - %d\n", rv);
658 rv = usb_translate_errors(rv);
659 }
660 } else {
661 rv = 0;
662 }
663 mutex_unlock(&desc->wlock);
664 if (desc->count == 1)
665 desc->manage_power(intf, 1);
666 usb_autopm_put_interface(desc->intf);
667 out:
668 mutex_unlock(&wdm_mutex);
669 return rv;
670 }
671
672 static int wdm_release(struct inode *inode, struct file *file)
673 {
674 struct wdm_device *desc = file->private_data;
675
676 mutex_lock(&wdm_mutex);
677
678 /* using write lock to protect desc->count */
679 mutex_lock(&desc->wlock);
680 desc->count--;
681 mutex_unlock(&desc->wlock);
682
683 if (!desc->count) {
684 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
685 dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
686 kill_urbs(desc);
687 spin_lock_irq(&desc->iuspin);
688 desc->resp_count = 0;
689 spin_unlock_irq(&desc->iuspin);
690 desc->manage_power(desc->intf, 0);
691 } else {
692 /* must avoid dev_printk here as desc->intf is invalid */
693 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
694 cleanup(desc);
695 }
696 }
697 mutex_unlock(&wdm_mutex);
698 return 0;
699 }
700
701 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
702 {
703 struct wdm_device *desc = file->private_data;
704 int rv = 0;
705
706 switch (cmd) {
707 case IOCTL_WDM_MAX_COMMAND:
708 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
709 rv = -EFAULT;
710 break;
711 default:
712 rv = -ENOTTY;
713 }
714 return rv;
715 }
716
717 static const struct file_operations wdm_fops = {
718 .owner = THIS_MODULE,
719 .read = wdm_read,
720 .write = wdm_write,
721 .open = wdm_open,
722 .flush = wdm_flush,
723 .release = wdm_release,
724 .poll = wdm_poll,
725 .unlocked_ioctl = wdm_ioctl,
726 .compat_ioctl = wdm_ioctl,
727 .llseek = noop_llseek,
728 };
729
730 static struct usb_class_driver wdm_class = {
731 .name = "cdc-wdm%d",
732 .fops = &wdm_fops,
733 .minor_base = WDM_MINOR_BASE,
734 };
735
736 /* --- error handling --- */
737 static void wdm_rxwork(struct work_struct *work)
738 {
739 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
740 unsigned long flags;
741 int rv = 0;
742 int responding;
743
744 spin_lock_irqsave(&desc->iuspin, flags);
745 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
746 spin_unlock_irqrestore(&desc->iuspin, flags);
747 } else {
748 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
749 spin_unlock_irqrestore(&desc->iuspin, flags);
750 if (!responding)
751 rv = usb_submit_urb(desc->response, GFP_KERNEL);
752 if (rv < 0 && rv != -EPERM) {
753 spin_lock_irqsave(&desc->iuspin, flags);
754 clear_bit(WDM_RESPONDING, &desc->flags);
755 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
756 schedule_work(&desc->rxwork);
757 spin_unlock_irqrestore(&desc->iuspin, flags);
758 }
759 }
760 }
761
762 /* --- hotplug --- */
763
764 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
765 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
766 {
767 int rv = -ENOMEM;
768 struct wdm_device *desc;
769
770 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
771 if (!desc)
772 goto out;
773 INIT_LIST_HEAD(&desc->device_list);
774 mutex_init(&desc->rlock);
775 mutex_init(&desc->wlock);
776 spin_lock_init(&desc->iuspin);
777 init_waitqueue_head(&desc->wait);
778 desc->wMaxCommand = bufsize;
779 /* this will be expanded and needed in hardware endianness */
780 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
781 desc->intf = intf;
782 INIT_WORK(&desc->rxwork, wdm_rxwork);
783
784 rv = -EINVAL;
785 if (!usb_endpoint_is_int_in(ep))
786 goto err;
787
788 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
789
790 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
791 if (!desc->orq)
792 goto err;
793 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
794 if (!desc->irq)
795 goto err;
796
797 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
798 if (!desc->validity)
799 goto err;
800
801 desc->response = usb_alloc_urb(0, GFP_KERNEL);
802 if (!desc->response)
803 goto err;
804
805 desc->command = usb_alloc_urb(0, GFP_KERNEL);
806 if (!desc->command)
807 goto err;
808
809 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
810 if (!desc->ubuf)
811 goto err;
812
813 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
814 if (!desc->sbuf)
815 goto err;
816
817 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
818 if (!desc->inbuf)
819 goto err;
820
821 usb_fill_int_urb(
822 desc->validity,
823 interface_to_usbdev(intf),
824 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
825 desc->sbuf,
826 desc->wMaxPacketSize,
827 wdm_int_callback,
828 desc,
829 ep->bInterval
830 );
831
832 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
833 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
834 desc->irq->wValue = 0;
835 desc->irq->wIndex = desc->inum; /* already converted */
836 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
837
838 usb_fill_control_urb(
839 desc->response,
840 interface_to_usbdev(intf),
841 /* using common endpoint 0 */
842 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
843 (unsigned char *)desc->irq,
844 desc->inbuf,
845 desc->wMaxCommand,
846 wdm_in_callback,
847 desc
848 );
849
850 desc->manage_power = manage_power;
851
852 spin_lock(&wdm_device_list_lock);
853 list_add(&desc->device_list, &wdm_device_list);
854 spin_unlock(&wdm_device_list_lock);
855
856 rv = usb_register_dev(intf, &wdm_class);
857 if (rv < 0)
858 goto err;
859 else
860 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
861 out:
862 return rv;
863 err:
864 spin_lock(&wdm_device_list_lock);
865 list_del(&desc->device_list);
866 spin_unlock(&wdm_device_list_lock);
867 cleanup(desc);
868 return rv;
869 }
870
871 static int wdm_manage_power(struct usb_interface *intf, int on)
872 {
873 /* need autopm_get/put here to ensure the usbcore sees the new value */
874 int rv = usb_autopm_get_interface(intf);
875
876 intf->needs_remote_wakeup = on;
877 if (!rv)
878 usb_autopm_put_interface(intf);
879 return 0;
880 }
881
882 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
883 {
884 int rv = -EINVAL;
885 struct usb_host_interface *iface;
886 struct usb_endpoint_descriptor *ep;
887 struct usb_cdc_parsed_header hdr;
888 u8 *buffer = intf->altsetting->extra;
889 int buflen = intf->altsetting->extralen;
890 u16 maxcom = WDM_DEFAULT_BUFSIZE;
891
892 if (!buffer)
893 goto err;
894
895 cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
896
897 if (hdr.usb_cdc_dmm_desc)
898 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
899
900 iface = intf->cur_altsetting;
901 if (iface->desc.bNumEndpoints != 1)
902 goto err;
903 ep = &iface->endpoint[0].desc;
904
905 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
906
907 err:
908 return rv;
909 }
910
911 /**
912 * usb_cdc_wdm_register - register a WDM subdriver
913 * @intf: usb interface the subdriver will associate with
914 * @ep: interrupt endpoint to monitor for notifications
915 * @bufsize: maximum message size to support for read/write
916 *
917 * Create WDM usb class character device and associate it with intf
918 * without binding, allowing another driver to manage the interface.
919 *
920 * The subdriver will manage the given interrupt endpoint exclusively
921 * and will issue control requests referring to the given intf. It
922 * will otherwise avoid interferring, and in particular not do
923 * usb_set_intfdata/usb_get_intfdata on intf.
924 *
925 * The return value is a pointer to the subdriver's struct usb_driver.
926 * The registering driver is responsible for calling this subdriver's
927 * disconnect, suspend, resume, pre_reset and post_reset methods from
928 * its own.
929 */
930 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
931 struct usb_endpoint_descriptor *ep,
932 int bufsize,
933 int (*manage_power)(struct usb_interface *, int))
934 {
935 int rv = -EINVAL;
936
937 rv = wdm_create(intf, ep, bufsize, manage_power);
938 if (rv < 0)
939 goto err;
940
941 return &wdm_driver;
942 err:
943 return ERR_PTR(rv);
944 }
945 EXPORT_SYMBOL(usb_cdc_wdm_register);
946
947 static void wdm_disconnect(struct usb_interface *intf)
948 {
949 struct wdm_device *desc;
950 unsigned long flags;
951
952 usb_deregister_dev(intf, &wdm_class);
953 desc = wdm_find_device(intf);
954 mutex_lock(&wdm_mutex);
955
956 /* the spinlock makes sure no new urbs are generated in the callbacks */
957 spin_lock_irqsave(&desc->iuspin, flags);
958 set_bit(WDM_DISCONNECTING, &desc->flags);
959 set_bit(WDM_READ, &desc->flags);
960 /* to terminate pending flushes */
961 clear_bit(WDM_IN_USE, &desc->flags);
962 spin_unlock_irqrestore(&desc->iuspin, flags);
963 wake_up_all(&desc->wait);
964 mutex_lock(&desc->rlock);
965 mutex_lock(&desc->wlock);
966 kill_urbs(desc);
967 cancel_work_sync(&desc->rxwork);
968 mutex_unlock(&desc->wlock);
969 mutex_unlock(&desc->rlock);
970
971 /* the desc->intf pointer used as list key is now invalid */
972 spin_lock(&wdm_device_list_lock);
973 list_del(&desc->device_list);
974 spin_unlock(&wdm_device_list_lock);
975
976 if (!desc->count)
977 cleanup(desc);
978 else
979 dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
980 mutex_unlock(&wdm_mutex);
981 }
982
983 #ifdef CONFIG_PM
984 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
985 {
986 struct wdm_device *desc = wdm_find_device(intf);
987 int rv = 0;
988
989 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
990
991 /* if this is an autosuspend the caller does the locking */
992 if (!PMSG_IS_AUTO(message)) {
993 mutex_lock(&desc->rlock);
994 mutex_lock(&desc->wlock);
995 }
996 spin_lock_irq(&desc->iuspin);
997
998 if (PMSG_IS_AUTO(message) &&
999 (test_bit(WDM_IN_USE, &desc->flags)
1000 || test_bit(WDM_RESPONDING, &desc->flags))) {
1001 spin_unlock_irq(&desc->iuspin);
1002 rv = -EBUSY;
1003 } else {
1004
1005 set_bit(WDM_SUSPENDING, &desc->flags);
1006 spin_unlock_irq(&desc->iuspin);
1007 /* callback submits work - order is essential */
1008 kill_urbs(desc);
1009 cancel_work_sync(&desc->rxwork);
1010 }
1011 if (!PMSG_IS_AUTO(message)) {
1012 mutex_unlock(&desc->wlock);
1013 mutex_unlock(&desc->rlock);
1014 }
1015
1016 return rv;
1017 }
1018 #endif
1019
1020 static int recover_from_urb_loss(struct wdm_device *desc)
1021 {
1022 int rv = 0;
1023
1024 if (desc->count) {
1025 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1026 if (rv < 0)
1027 dev_err(&desc->intf->dev,
1028 "Error resume submitting int urb - %d\n", rv);
1029 }
1030 return rv;
1031 }
1032
1033 #ifdef CONFIG_PM
1034 static int wdm_resume(struct usb_interface *intf)
1035 {
1036 struct wdm_device *desc = wdm_find_device(intf);
1037 int rv;
1038
1039 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1040
1041 clear_bit(WDM_SUSPENDING, &desc->flags);
1042 rv = recover_from_urb_loss(desc);
1043
1044 return rv;
1045 }
1046 #endif
1047
1048 static int wdm_pre_reset(struct usb_interface *intf)
1049 {
1050 struct wdm_device *desc = wdm_find_device(intf);
1051
1052 /*
1053 * we notify everybody using poll of
1054 * an exceptional situation
1055 * must be done before recovery lest a spontaneous
1056 * message from the device is lost
1057 */
1058 spin_lock_irq(&desc->iuspin);
1059 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1060 set_bit(WDM_READ, &desc->flags); /* unblock read */
1061 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1062 desc->rerr = -EINTR;
1063 spin_unlock_irq(&desc->iuspin);
1064 wake_up_all(&desc->wait);
1065 mutex_lock(&desc->rlock);
1066 mutex_lock(&desc->wlock);
1067 kill_urbs(desc);
1068 cancel_work_sync(&desc->rxwork);
1069 return 0;
1070 }
1071
1072 static int wdm_post_reset(struct usb_interface *intf)
1073 {
1074 struct wdm_device *desc = wdm_find_device(intf);
1075 int rv;
1076
1077 clear_bit(WDM_OVERFLOW, &desc->flags);
1078 clear_bit(WDM_RESETTING, &desc->flags);
1079 rv = recover_from_urb_loss(desc);
1080 mutex_unlock(&desc->wlock);
1081 mutex_unlock(&desc->rlock);
1082 return 0;
1083 }
1084
1085 static struct usb_driver wdm_driver = {
1086 .name = "cdc_wdm",
1087 .probe = wdm_probe,
1088 .disconnect = wdm_disconnect,
1089 #ifdef CONFIG_PM
1090 .suspend = wdm_suspend,
1091 .resume = wdm_resume,
1092 .reset_resume = wdm_resume,
1093 #endif
1094 .pre_reset = wdm_pre_reset,
1095 .post_reset = wdm_post_reset,
1096 .id_table = wdm_ids,
1097 .supports_autosuspend = 1,
1098 .disable_hub_initiated_lpm = 1,
1099 };
1100
1101 module_usb_driver(wdm_driver);
1102
1103 MODULE_AUTHOR(DRIVER_AUTHOR);
1104 MODULE_DESCRIPTION(DRIVER_DESC);
1105 MODULE_LICENSE("GPL");
Linux with added FPC-III support